by USA TODAY sports staff, USA TODAY Sports

by USA TODAY sports staff, USA TODAY Sports

INDIANAPOLIS - Dario Franchitti couldn't risk another head injury, his IndyCar Series team owner said Friday.

"A repeat of that kind of concussion could be serious," Chip Ganassi said in a conference call.

Franchitti suffered a concussion in his Oct. 6 crash in Houston, and while specifics of his injury haven't been revealed, Ganassi said recent neurological tests in Miami led doctors to advise retirement.

Franchitti, who is in Scotland, has not been reached for comment. But he said in a press release Thursday that head and spinal injuries suffered in the crash - in which his car went airborne into a catchfence on the last lap and landed back on the track -- forced him to stop racing.

Ganassi said Franchitti was "heartbroken" to give the news, saying that the telephone call he received from the three-time Indianapolis 500 winner and four-time IndyCar Series champion sounded different than all other conversations he's had with him.

"His voice was different, his demeanor was different," Ganassi said. "He was certainly heartbroken. He's a bit of a realist about it, too. I went through all the obvious questions. He said, 'Look, I don't want to go forward. I'd never want to go forward and risk hurting somebody else or risk further injury, much less hurt somebody else.' He wouldn't dare risk giving a black eye to the sport or something by trying some sort of end around. That was out of the question. He respects professionals."

Franchitti had two surgeries on his broken ankle, one in Houston and one in Indianapolis, before traveling in the last two weeks to Miami to see IndyCar consultant Steve Olvey. The 40-year-old Franchitti then returned home to Scotland to continue his recovery.

He was in Scotland when he was advised to stop. Olvey, the associate professor of Clinical Neurology/Neurosurgery at the University of Miami-Miller School of Medicine, told RACER.com that Franchitti has suffered three concussions since 2002 and the one at Houston "was a big one, a significant concussion.

"He's got a higher risk for future concussions with less energy involved in a crash," Olvey told RACER. "And, as we've seen in pro football, repeated concussions can lead to early dementia, so he's got to think of his future. It's just too great a risk to take."

Ganassi said Franchitti will heal.

"Medically he has been told he'll make a 100 percent recovery, we've been told that from day one," Ganassi said. "These are all injuries that are recoverable. I don't want anybody thinking he's maimed for life."

Continuing against the recommendation of experts "is not even close to his style," Ganassi said.

Baseline testing in NASCAR

Franchitti's retirement was still reverberating through the sport. Jimmie Johnson, who goes for his sixth NASCAR championship Sunday, said he feels horrible for his good friend.

"In one light, it shows just how bad his crash was. I'm just happy he is in good health," Johnson said. "My heart goes out to him from the perspective of having racing taken from him before it was time. That's got to be so tough to deal with. Everyone wants to walk away on their terms."

Franchitti's mentor, Jackie Stewart, said the four-time IndyCar champion is exiting on top and will be an asset outside of the car.

"There's not much more he could achieve in American motor racing," Stewart said at the U.S. Grand Prix in Austin. "I think he's one of the real players in the business. He's got a strong future in front of him because of the success he's achieved in racing. Sad for motor racing because he's a great asset to us: A great looking guy, very eloquent and he's very fast."

Franchitti could also be the unofficial face of the importance of baseline concussion testing in racing.

NASCAR is mandating the testing beginning next season, in part because of the two concussions Dale Earnhardt Jr. suffered last year. Earnhardt Jr. missed two races while recovering.

NASCAR will use the ImPACT test to measure verbal and visual memory, processing speed and reaction time, and determine if a driver is medically able to race following a concussion.

NASCAR President Mike Helton did not say Friday that Franchitti's injury validated NASCAR's decision to implement the testing. But he acknowledged the industry takes note when a champion driver has to get out of the car. Three-time NASCAR champion Tony Stewart has been out since August with a broken leg, and Denny Hamlin missed several races earlier this year with a fractured vertebra.

"I think it has a huge effect on all of the motorsports industry when a caliber of driver like Dario says he's not going to get back in the car," Helton said.

Defending NASCAR champion Brad Keselowski has been outspoken in his opposition of the testing, which has long been required in IndyCar.

"Doctors don't understand our sport. They never have. Doctors aren't risk takers. We are," Keselowski has said. "That's what makes our sport what it is. When you get doctors involved, you water down our sport."

While not asked specifically about Keselowski, Ganassi referenced his stance while supporting the testing.

"Let's just say I'm probably 180 degrees different than the current NASCAR champion feels about having doctors around, their input," he said. "That statement comes from experiences that I've had personally. To break a bone is one thing, or to have a surgical procedure is another.

"But when it comes to your head, I think it's important that everybody understands that's probably the least known area of expertise by any doctor, and certainly there's a lot of expertise out there. They're just in the last four or five years understanding what injuries and implications of those injuries are."

Who will replace Franchitti at TGR?

As for Franchitti's replacement in the Target-sponsored No. 10 car, Ganassi conceded that Indianapolis 500 champion Tony Kanaan, who was signed to the team before Franchitti's accident, will be a candidate. The team is committed to fielding four cars, he said, with IndyCar Series champion Scott Dixon driving the No. 9 car and Charlie Kimball the No. 83.

Ganassi said hiring a young driver is something team officials will consider in the coming weeks, but he seemed more likely to follow the advice of longtime friend and former staff member Morris Nunn, who often said, "You need to take the best driver available and don't think about anything else."

"I would love the opportunity to give a young guy a chance," Ganassi said. "I think there are better places for young people to come into the sport than into that 10 car.

"Whoever fills that seat not only has obviously big shoes, if not the biggest shoes to fill in the sport, but you're also somebody that has to be a huge teammate and able to help Scott Dixon, as well, and Kanaan and Charlie.

One former IndyCar champion who has said he is not interested in replacing Franchitti is Sam Hornish Jr.

Hornish, who won IndyCar championships in 2001, '02 and '06, said Target Chip Ganassi Racing reached out to his representatives this week but he is committed to remaining in NASCAR. Hornish will battle Austin Dillon for the NASCAR Nationwide Series championship Saturday at Homestead-Miami Speedway.

"I expressed I was very grateful even for the call," Hornish said Friday. "A door opens and the reason still stands to not do it. It's just any time I've had a thought or thought about that at all, it's been like very minimal.

"I've said it a million times: I did everything over there that I wanted to do, and way more. The only goal I had when I started racing was to go to the Indianapolis 500. I look at that as a chapter in my life."

This story was compiled from Curt Cavin, who writes for the Indianapolis Star, and the Associated Press.